1. Field of the Invention
The invention relates to an improved tool for electrochemical machining of a fuel injection device.
2. Description of the Prior Art
Fuel injection devices are components of fuel injection systems. With these systems, fuel can be delivered from a tank to the combustion chambers of an internal combustion engine. Pumps, in particular high-pressure pumps, can be used, which subject the fuel to pressure and deliver it to the fuel injection devices. The fuel injection devices typically have a housing in which a plurality of chambers are provided for carrying and/or holding fuel. Between these chambers, sharp-edged transition regions may be embodied, especially whenever the individual chambers are made by metal-cutting machining. In the regions of the sharp-edged transitions, burrs can be formed, which have to be removed before the fuel injection device is put into operation.
In addition to mechanical methods, the possibility exists of removing these burrs by way of electrochemical machining. Such a method provides that an electrode, connected as a cathode, is brought to a machining region of a fuel injection device that is to be deburred, the latter being connected as an anode. An electrolyte fluid can be delivered to the machining region, and as a result, electrochemical reactions take place at the electrode connected as a cathode and at the workpiece connected as an anode. At the anode, positively charged cations are removed, which together with hydroxide ions react to form a metal hydroxide and settle out as sludge. At the cathode, various chemical reduction reactions take place.
The method described is quite suitable for enabling a defined quantity of material to be removed from the housing of a fuel injection device. However, especially in undercut regions of the housing, it can be difficult to position the electrode in the fuel injection device in such a way that an optimal work gap is formed between the electrode and the work region.
With this as the point of departure, the object of the present invention is to further develop a tool for electrochemical machining of a fuel injection device such that deburring, with good material removal rates, is made possible even in undercut regions of the fuel injection device.